Cap for containers and the like and method of producing the same



April 1937. F R, R U R 2,076,158

GAP FOR CONTAINERS AND THE LIKE AND METHOD OF PRODUCING THE SAME FiledJune 2, 1954 7 I INVE TOR 1 7M 6* M Patented Apr. 6, 1937 K am ss PATENTCAP FOR CONTAINERS AND THE LIKE AND METHOD OF PRODUCING THE SAMEFrederick R. Reutter, Waterbury, Conn, assignor to Scovill ManufacturingCompany, Waterbury, Conn, a corporation of Connecticut Application June2, 1934, Serial No. 728,658

4 Claims.

This invention relates to caps for containers and the like and a methodof producing the same.

Various users of caps, for example, packagers of toilet articles, drugsand food preparations have come to demand closures that present anundefaced and unbroken outer surface, and that make a substantiallyuninterrupted joint with the container body.

It is an object of the present invention to provide a one-piece metalcap that has an internal uninterrupted thread for engagement with thethread of a container or the like, at the same time having an undefacedouter surface.

It is a further object of the invention to provide a method of producingsuch a cap.

With these general objects in view the invention consists in thefeatures, combinations, details of construction and arrangements ofparts which will first be described in connection with the accompanyingdrawing and then more particularly pointed out.

In the drawing:

Fig. 1 is a view partly in elevation and partly in vertical section of acontainer and a cap therefor constructed in accordance with theinvention;

Fig. 2 is a bottom plan View of the cap;

Fig. 3 is a schematic development of the cap blank;

Fig. 4 is a similar view of the completed cap;

Fig. 5 is a sectional view (enlarged) taken on the imaginary line 55 ofFig. 3;

Fig. 6 is a similar view on the imaginary line 6-6 of Fig. 4; and

Fig. '7 is a sectional view taken on the line 'll of Fig. 2.

Referring to the drawing, the container here illustrated as an exampleis a wide-mouthed jar ll having a neck l2 somewhat reduced in diameterto leave a shoulder l3. On the neck I2 is a thread l4.

The container is closed by a one-piece metal cap [5 having a top portionI6 and a skirt H. The cap skirt is designed to take over the neck of the4,5 jar and is of a diameter substantially the same as the outerdiameter of shoulder l3. The outer face of the skirt l'l presents asmooth, unbroken or undefaced surface and has an uninterrupted bottomedge, making a neat joint with the container.

In accordance with the invention in its entirety, the inner wall of thecap skirt is provided with a continuous thread-like element extendingaround the greater portion of its periphery and formed from metalintegrally rooted to the skirt wall.

As here shown as example, the inner wall of the cap skirt has abead-like thread it extending around its periphery in a helical path toaccord with the pitch lineof the container thread IA. The bead is formedfrom a narrow band of metal one edge of which is integrally rooted tothe skirt wall.

This may be accomplished, for example, by shaving a band of metal fromthe inner wall of the cap skirt, leaving the upper edge of said band 10integrally rooted to the wall, and forming the shaved metal into thehelical thread-engaging element, e. g. rolling it into bead-like form.Since the ultimate thread-like element is on a pitch line and sincethere must be an entrance for the 15 container thread, it will beunderstood that the shaved band does not extend around a full 360. Theadjacent ends are separated by a gap of any desired and practicallength, such as the gap indicated in Figs. 2, 4 and 7. 20

In carrying out the invention to what is now considered the bestadvantage, the thread-like element l8 has a substantially uniform degreeof roll throughout its peripheral length. This may be accomplished, forexample, by providing the 25 wall of the skirt of the blank with ahelical edge, and starting the cut from such edge, the depth of the outbeing substantially equal throughout the peripheral length of the band.This results in a band of uniform depth and, consequently, in 30 auniform degree of roll.

The helical edge from which the cutting is started may be an interioredge or a bottom edge. The drawing illustrates a cap blank having aninterior edge. As there shown as an example, the 5 skirt of the capblank (Fig. 5) has an. upper portion thicker than the lower portion. Toattain this end and still preserve an unbroken outer surface, the innerwall of the skirt blank is formed. in any suitable manner, with twosurfaces, one 40 offset from the other, thereby providing a downwardlyfacing shoulder It. This shoulder, moreover, follows a helical path toaccord with the pitch line of the container thread. The band of metal isthen shaved from the thicker portion of ,5 the inner wall of the skirt,starting the cut at the interior helical edge provided by shoulder 19and the out is given an equal depth throughout its peripheral length. Asa result, the rolled up bead is on a helical line but has a uniformdegree of 00 roll throughout.

If desired, the cut may be started from a bottom edge. In that case, theskirt of the blank may be of uniform thickness, and is formed with ahellcal bottom edge. Because of this helical bottom 55 edge, the skirtof the blank is made longer than the desired cap skirt. The shaving isstarted from the helical bottom edge of the cap blank, the out againhaving a uniform depth throughout its 5 peripheral length. To completethe cap, the edge of the skirt of the blank is cut off on a right line,below the thread, to true the edge and to give the skirt the desiredlength.

If desired, the skirt of the cap blank may, in

any event, be made longer than the desired skirt and cut down to properfinal length after the shaving and rolling operation. This is indicatedby the broken lines in Fig. '7.

What is claimed is:

1. A one-piece metal screw cap for containers or the like, comprising atop portion and a skirt, the skirt having an undefaced outer surface,and the inner wall of the skirt having a continuous thread-like beadextending around the greater portion of its periphery in a helical pathand formed from metal integrally rooted to said inner wall, said beadhaving a substantially uniform degree of roll throughout its peripherallength.

2. The method of forming a metal screw cap for containers and the like,which comprises forming a cap blank having a top portion and a skirt,

said skirt having a helical edge, shaving a continuous band of metalfrom the inner wall of the skirt around the greater portion of itsperiphery, starting the cut at said edge and leaving said bandintegrally rooted to said wall, the depth of out being substantiallyequal throughout the peripheral length of the band, and forming saidband into a thread-like element.

3. The method of forming a metal screw cap for containers and the like,which comprises forming a cap blank having a top portion and a skirt,said skirt having a helical edge, shaving a continuous band of metalfrom the inner wall of the skirt around the greater portion of itsperiphery, starting the cut at said edge and leaving said bandintegrally rooted to said wall, and rolling up said band into athread-like head.

4. A one-piece metal screw cap for containers or the like, comprising atop portion and a skirt, the skirt having an undefaced outer surface,and the inner wall of the skirt having a single threadlike beadextending around the greater part of its periphery, said bead beingformed from metal shaved from and integrally rooted to said inner wall.

FREDERICK R. REUTTER.

